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Pages 1-38

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From page 1...
... National Geodetic Survey, operating under a series of interagency agreements with the FAA, is responsible for certifying that information developed from obstructions surveys meets the requirements for operation of the LIGHT DETECTION AND RANGING (LIDAR) DEPLOYMENT FOR AIRPORT OBSTRUCTIONS SURVEYS This digest presents the results of ACRP Project 3-01, "Light Detection and Ranging (LIDAR)
From page 2...
... describe the technical bases that could justify acceptance of LIDAR-based obstructions surveys by NOAA's National Geodetic Survey (NGS) , FAA, airports, and airlines.
From page 3...
... Survey contractors involved in these survey projects did not release information on specific survey costs and survey-design details for the cases identified by the research team. However, the research team was able to verify that a variety of vendors provide airborne LIDAR data collection and processing equipment and services suitable for use in an airport obstruction survey.
From page 4...
... A sample specification, developed by the research team and included as the appendix to this digest, assumes that stereo imagery will be available to support interpretation of LIDAR data. The specification addresses four key aspects of data acquisition and processing: • Calibration tests: Radiometric qualification tests for obstruction detection and system calibration (factory calibration, field calibration by flying over a building site of known topography, and in-flight calibration)
From page 5...
... Data Acquisition & Processing 5.1 Acquisition of aerial photo 5.2 Initialization/calibration of Airborne GPS & IMU 5.3 QA/QC for image quality 5.4 Scan aerial film; submit for approval 5.5 Tie and pass point measurements 5.6 Measure ground control points 5.7 Refine aerotriangulation (AT) /bundle adjustment 5.8 Submit AT report for approval 5.9 Receive LIDAR products 5.10 Conduct obstruction survey analysis Use Photo & LIDAR data (DEM, Surface model)
From page 7...
... docum ent are intended for conducting airborne LIDAR surveys and using the ìpoint clo ud" data in com bination with aerial im agery for airport obs tr uction analysis. However, th is document is not approved by the Federal Aviation Administration at this time and it shall not be considered as an interpretation or stat em ent of FAA policy.
From page 8...
... Additional project instructions included in contract agreement for an airport will provide project-specific survey information. General specifications, standards, guidelines, and additional requirements for airport obstruction surveys are contained in the following FAA ACs: AC 150/5300-16A, General Guidance and Specifications for Aeronautical Surveys: Establishment of Geodetic Control and Submission to the National Geodetic Survey, September 15, 2007.
From page 9...
... Additionally, swath overlap, cross-lines, and other mission planning parameters must be carefully planned based on the unique considerations involved in airport obstruction surveying, including precautions taken to avoid missed objects, as illustrated in Figures 9.1, 9.2, and 9.3. (See Sections 9.1 and 9.2)
From page 10...
... . More recent information regarding these accuracy requirements and OIS is found in the following FAA ACs: AC 150/5300-17B, General Guidance and Specifications for Aeronautical Survey Airport Imagery Acquisition and Submission to the National Geodetic Survey, US Dept.
From page 11...
... Accuracy checkpoints for LIDAR can be the same locations used for imagery accuracy checkpoints and imagery control GPS ground stations. These accuracy checkpoints are not to be confused with the ground GPS base station data required and used for post-processing airborne GPS data for both LIDAR and aerial imagery.
From page 12...
... 3.4 COMPLETION DATE All deliverables shall be received by FAA/NGS, as specified, no later than the date in the project instructions. 4 EQUIPMENT AND MATERIAL 4.1 LIDAR SYSTEM The Contractor shall have several options in deploying the LIDAR sensor for OIS surveys (see Table 4.1)
From page 13...
... Proceed with OIS analysis steps as suggested in Figure 14.1. Single-look, relying primarily on photogrammetric methods for obstruction detection First set of passes parallel to runways Cross/tie lines at end(s)
From page 14...
... ALTERNATIVE #2 - The Contractor shall fly parallel flight lines (with 50% swath overlap) in opposing directions (reciprocal headings)
From page 15...
... . Unless otherwise stated in the project instructions, horizontal point spacing must meet the specifications contained in Table 5.1 of this document.
From page 16...
... The objective of the test procedures described here is to radiometrically qualify LIDAR systems for airport obstruction surveying. The outputs of this test are the maximum qualified operating height, hma δmin ρ0 x, for the system and the minimum ground sampling density, , for that system.
From page 17...
... Figure 6.1 Setup for radiometric qualifications test to be performed at the NOAA LIDAR Radiometric Calibration Center at Corbin, VA. Distant Beam Stop Reflective Dowel x Lidar Under Test R0 For each angular condition tested, the laser shall be fired at the test target for at least 10 seconds and the return signal shall be recorded.
From page 18...
... Then, the minimum sample density requirement for this system shall be: (7.5) When this test has been carried out under the oversight of NOAA personnel at the NOAA LIDAR Radiometric Calibration Center (LRCC)
From page 19...
... The calibration reports shall cover each of the following types of calibration: 8.1 FACTORY CALIBRATION Factory calibration of the LIDAR system shall address both radiometric and geometric performance and calibration. (Note: the factory radiometric calibration does not obviate the need for the radiometric qualification test for obstruction surveying described in the previous section)
From page 20...
... Figure 8.1 Example of test apparatus deployed in survey area, stabilized by supports and weights. 8.3.2 Placement As practical as possible, the test device shall be placed in a safe, open area, within a normal section of the OIS survey area.
From page 21...
... NGS may supply recommendations and/or requirements for planning parameters in the project instructions. The planning of an OIS survey is not like the planning of a terrain survey.
From page 22...
... SWATH OVERLAP – Adjacent swaths shall have a minimum overlap of no less than 50% of the mean swath width.
From page 23...
... , or shapefiles, or KML/KMZ files clearly showing all proposed flight lines, and also depicting coverage, proposed ground control, and OIS boundaries. Information about scan angle, pulse repetition frequency (PRF)
From page 24...
... Imagery acquisition shall be performed by the Contractor no later than 2 weeks following the completion of the LIDAR data acquisition, and no earlier than 2 weeks prior to the commencement of the LIDAR acquisition. No exception to the ± 2 week window is allowed without prior written approval from NGS or unless waived in the project instructions.
From page 25...
... for positioning in the NSRS, even if the ground station is set up over a known survey monument in the NGS Database. (See Section 20 for terminology related to ground GPS data collection.)
From page 26...
... For additional specification guidance on mark setting, GPS observations, data processing, and data submittal in NGS format, see FAA AC 150/5300-16A and the "General Specifications for Aeronautical Surveys, Volume I, Establishment of Geodetic Control on Airports" at: www.ngs.noaa.gov/AERO/Supinst.html www.ngs.noaa.gov/FGCS/BlueBook/ www.ngs.noaa.gov/PROJECTS/FBN/ 13.3 AIRCRAFT GPS RECEIVER A GPS OBSERVATIONS – The aircraft's GPS receiver shall be able to collect carrier phase observations and record, at least, once per second, from a minimum of four satellites (five or more preferred)
From page 27...
... If multiple ground stations were used, provide processing details, coordinates, and accuracy for all stations.
From page 28...
... are often applied in post-processing. For airport obstruction surveying, this type of cleaning is O ption 1 Perform OIS Analysis Perform QA/QC Steps Attribute Objects Run Object Detection Algorithm Unfiltered LIDAR Point Cloud Data Containing all Returns Collate Objects Imagery Step 1 Step 2 Step 3Step 4 Option 2 very dangerous, as it can easily lead to removing points corresponding to reflections from obstructions, in some cases causing these obstructions to be missed.
From page 29...
... Additional or custom deliverables may be described in individual project instructions. The Contractor is also responsible for providing all required deliverables in FAA AC 150/5300-16A, FAA AC 150/5300-17B, and FAA AC 150/5300-18B.
From page 30...
... Indicate which GPS points are pre-existing ground control and which stations are new and positioned relative to the NSRS. See project instructions and Sections 3.1 C and 12.2.
From page 31...
... Ground Control Report, including a station list in table format; 6. Aircraft Navigation; 7 Airborne kinematic GPS Report, including ground stations; 8.
From page 32...
... FAA AC 150/5300-16A , General Guidance and Specifications for Aeronautical Survey Airport Imagery Acquisition and Submission to the National Geodetic Survey . Federal Aviation Administration, Washington, DC.
From page 33...
... For directly-georeferenced airborne remote sensing projects (e.g., acquisition of LIDAR or directly-georeferenced aerial imagery) , the GPS base station data are used in post-processing the airborne kinematic GPS data.
From page 34...
... Setting up GPS base stations used for LIDAR and aerial imagery acquisition over PACS or SACS, and tying airport GCPs to the PACS and SACS, therefore ensures datum consistency for airport-specific applications. 20.4 Check Point Check points are GCPs specifically intended or used for assessing the spatial accuracy of the data.
From page 35...
... OIS Obstruction Identification Surface OPUS Online Positioning User System PACS Prim ary Airport Control Station PDOP Position Dilution of Precision POS Position Orientation System PRF Pulse Repetition Frequency RGB Red Green Blue RMSE Root Mean Squared Error SC Survey Acquisition Contractor or Survey Contractor SACS Secondary Airport Control Station SML Surface Model Library SOW Statem ent of Work or Scope of work UTC Coordinated Universal Time -- formerly known as Greenwich mean time (GMT) VOs Vertical Objects VPS Vertical Point Spacing
From page 38...
... . Persons wanting to pursue the project subject matter in greater depth should contact the CRP Staff, Transportation Research Board of the National Academies, 500 Fifth Street, NW, Washington, DC 20001.


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